Process and apparatus for purifying gases



y E. A. PRUDHOMME 1,760,522

PROCESS AND APPARATUS FOR PURIFYING GASES Filed April 7, 192a PatentedMay 27, 1930 UNITED STATES.

PATENT OFFICE EUGENE ALBERT PRUDHOMHE, OF NEUILLY-SUR-SEINE, FRANCE,ASSIGNOR TO 50- CIETE INTERNATIONALE DES PBOCEIDES PRUDHOMME (S. I. P.19.), O1 PARIS, FRANCE, A LIMITED JOINT STOCK COMPANY OF FRANCE PROCESSAND APPARATUS FOR PURIFYING GASES Application sued April 7, 1926, Serialin. 100,462, and in France March 4, 1926.

The present invention relates to processes and apparatuses for the hotdesulphurization of gases derived from the distillation or the pyroenation of solid, liquid or other com- 5 busti les.

The applicant has recognized and has already drawn attention, in priorpatents, to the vital importance of purifying, principally thedesulphurization of such gases before they are submitted to the actionof catalysts, in the presence eventually of additional gases, and with aview to their enrichment and their reduction in density for theformation of synthetic liquid fuels. Catalysis without priorpurificationis practically inoperative, for'the reason that thecatalysts rapidly become contaminated c'easingthen to exercise thecatalytic action which is required of them. In particular when with aview to a polymerizing and fixation action of hydrogen, catalysts areemployed, as in the Prudhomme processes, in a cycle of operationswherein the maintenance of a constant temperature preventing anycondensation of tars is indispensable, the efiicient purification,before catalysis, is imperative,

The invention relates to means for ensuring sucha purification beforecatalysis, in a methodical manner, with the desired temperatureconditions.

The roblem of the elimination of sulphur, the principal object "of thepurification, is complex. It isnecessary not merely to operate in amanner to retain the inorganic sul- 5 .phur, but it is necessary toretain the organic sulphur, in the presence or in the absence of A Ysteam according to the nature of the combustibles treated; provided thatthis result does not cause by some manner or other a chemical alterationof the gases or vapours thus desulphurized. Finally practically, it isnecessary that the installation provided be such as to permit acontinuous industrial operation and the recuperation of the sulphur ina. commercial form. r

According to the invention, a practical solution of this complex problemis obtained, in principle, bythe following means The gases or vapours tobe desulphurized are conducted through a plurality of purihydrocarbons.

vmaintenance of a temperature suflicientlyf slightly elevated 'to avoidany disturbance of the chemical equilibrium of the desulphurized bodies.

In practice the purifiers in series are employed n two parallel groups,the plant thus permitt ng continuous operation, by regeneration of thepurifiers of the one group durmg the run of the other. i

The accompanying drawing shows, diagrammatically, a plant capable ofserving at will for the purification of gases containing or notcontaining steam, and the regeneration m a continuous operation of thepurifiers.

As shown on the drawing, the installation GOIIIPI'ISBS'tWO arallelgroups of purifiers, A, B, C and A, C The gases to be purified commgfrom producer. apparatuses by a p pe D, are led to the purifiers A, B, Cby a pipe d whilst.v the purifying masses of the apparatuses A B C arebeing regenerated or, alternatively, to these latter, by a pipe (lwhilst regeneration is being eflected in In these two batteries ofapparatuses the purifiers on admission A, A arecharged with a substancesuch as finely divided oxides of nickel placed upon a porcelain or othersupport (clinker, pumicestone, porous earth), these finely dividedoxides having for their function the retention more particularly of theinorganic sulphur. On leaving the apparatuses A, A the gases are led byE or E to the purifiers B or B charged with oxides of copper, iron orother suitable metal, placed on a similar support, these oxides being inall cases adapted to retain all the organic sul- Ehur leaving orremaining in the gases to e purified.

If the gases to be purified are free from steam, their passage throughthe two purifiers in series A, B or A, B effects their com- !pletepurification, this division of the purication into two steps permittingas has been stated, the conservation, in the apparatuses, of atemperature which ensures the maintenance of the chemical equilibrium ofthe gases to be purified.

If, on the contrary, the gases to be puri- Fed contain steam, such steamin acting on the cop er or other sulphides formed in B and B by thecombination of the purifying metal with the organic sulphur, may re ormsulphuretted hydrogen.

In order to ensure the separation of the sulphur out of the reformed H8, the gases to be purified are caused, according to the invention, topass by a pipe (G or G into a third purifier (C or C charged like thefirst of the series (A or A with material capable of retaining theinorganic sulphur, thus freeing the hydrogen from the reformedsulphuretted hydrogen.

It may here be remarked that the step by step purification and themaintenance of a suitably reduced temperature (250 C. for example)enables purification to be effected whilst however avoiding condensationof the vapours. in the apparatuses, by the condition that precautionsare taken in order that those of the vapours which normally would belikely to condense at such temperature, are mechanically entrained, byvirtue of a sulficient velocity conveyal obtained either by a suitableformation of the apparatuses and pipes, or by the addition of carriervapours or gases (steam or water gas, for example). I

The regeneration of the battery of purifiers A, B, C for example, can beeffected as follows The admission cock H leading to ABC, is closedwhilst the admission cock H to the purifiers A B -C previouslyregenerated is opened. Obviously the delivery cock I for the purifiedgases is closed and I opened.

Regeneration can be carried out in the known manner, by means of acurrent of air, the air being caused, according to the invention, to bepassed previously through a heater; it can e eflt'ected equally well,according to the invention, by means of a current of water gas chargedwith steam having passed previously through a heater maintained at atemperature of about 350 C.

In the example shown, provision has been made for the simultaneousemployment of both these two means, that is to say, regeneration bheated air for the apparatuses A and b Ceated water gas, for theapparatuses B an The air is admitted by a pipe J, provided with a cockthen open, into a heater K, from whence it is directed, through an opencock m, pipe M, open cock n and pipe N, into the purifying element A,from which the sulphur is removed, the sulphur dioxide formed leaving bythe pipe 0, the cock 0 then being open. The SO formed is collected in avat P charged with water.

Water gas is likewise led, by a pipe Q, and through an open cock 9, to aheater maintained at a temperature of about 350 C., and, the cooks r and8 being open, such gas traverses the elements B and C where the sulphuris removed from the sulphides, the snlphuretted hydrogen which is formedbeing conducted through an open cock :5 and pipe T, into the vat P.During this operation of regeneration, the temperature rises in theelements A, B and C; this is why it is necessary to bring these backbefore they are set in operation, to the normal temperature of purication, which is about 250 C. This result is obtained by cutting out theheater, by closure of the cocks j, m, 9,1- and by passing through theelements a stream of cold gas admitted by J and Q and led to the saidelements by JN and QS respectively, the cocks 7' 71. and

' g, 1 being open.

It can be seen that the elements A, B, C being reset in operation, theregeneration in the elements A, B C which were then in operation can beproceeded with, this being effected by a suitable setting of the seriesof cocks.

A pipe F is provided in shunt around the last purifier C and C for thepurpose of cutting out by the closure of suitable cocks this lastpurifier when the gasesto be treated do not contain steam.

Claims:

1. A continuous process for desulphurization of gases which consists inheatmg said gases successively in the presence of nickel oxide to removemineral sulphur therefrom and in the presence of copper oxide to removeorganic sulphur therefrom.

2. Apparatus of the class described comprising a plurality of purifyingelements arranged in series, means connecting said elements forconducting gases therebetween, and regeneratin means including aplurality of heaters and means connecting each of said heaters withseparate elements for separately delivering regenerating fluid to thelatter.

3. Apparatus of the class described comprising a plurality of purifyingelements, means connecting said elements in series, a bypass for thelast element of the series, and regenerating means for said elementsincluding a plurality of heaters, means connecting one of said heaterswith the first element and one with the last element for conductingregenerating fluid thereto, a by-pass for eachof said heaters and meansconducting said regenerating tluid from said elements.

4. Apparatus of the class described com prising at least nected inseries, heaters connected to the first and last elements of said seriesfor conducting regenerating fluid thereto, and means connected to thefirst and intermediate elements for conveying regenerating fluidtherefrom.

5. Apparatus of the class described comprising parallel series ofpurifying elements, a by-pass for the last element of each series, andmeans eluding a plurality of heaters and means connecting each of saidheaters with one of said elements of each series for separatelyconducting regenerating fluid thereto.

6. Apparatus of the class described comprising parallel seriesofpurifying elements, a by-pass for the last element of each series, andmeans for regenerating one of said series of elements While the otherseries is operating, said means including a plurality of heaters, meansconnecting each of said heaters to separate elements of each series, anddelivery conduits connected to each series.

7 Apparatus for the purification of gases comprising parallel series ofpurifying elements, a by-pass for the last element of each series, andregenerating means including a pair of heaters, one of said heatersbeing connected to the first element of each series and one to the lastelement of each series, a by pass for each heater, delivery conduitsconnected to elements of each series, and a water bath, said deliveryconduits being adapted to deliver regeneratin ments to said water ath.

In testimony whereof specification.

EUGENE ALBERT PRUDHOMIME.

I have signed this three purifying elements confor regenerating saidelements inmedium from said ele-

